Category Archive: Physics

Myths, Misconceptions and Misunderstandings

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In late 2012, applied mathematician Samuel Arbesman released an intriguing little book called ‘The Half-Life of Facts’ in which he seeks to explain why a lot of the information that we all thought we knew is continually being disproven. It’s an interesting read, but the central premise should really come as no surprise. After all, science is based upon a continued quest for the refinement of knowledge, in which no theory, no matter how precious, is allowed to become immune to refutation. Still, there remains a stalwart group of pseudo scientific ‘facts’ that possess the peculiar ability to survive intact, even in the face of new contradictory evidence. So in the spirit of public service, and with the hope of helping to cleanup mankind’s collective meme pool, here’s a list of some of science’s most common misconceptions.   5) Bulls are enraged by the colour red This myth is so prevalent it’s even become the basis for a common British …

Star trails in the southern skies

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The movements of the heavens above are sometimes hard to notice. This photo, however, shows clearly the stars rotating around the Earth’s rotational axis. The telescope in the foreground is the Yepun telescope (UT4) in the Very Large Telescope (VLT) complex at Paranal Observatory, Chile. The picture was taken by Farid Char, an astrophotographer from Chile. I asked him a few questions about his magnificent picture: How long does it take to create the picture? The photo is an artistic composition. I took several captures, then stacked them, but I superimposed a single frame to see the telescope quiet, otherwise it would appear distorted because of its continuous movement during the night. The basics of the picture are shown on its web section, but I can tell you is a composition of 867 single captures over a tripod (15” each), and the overall exposition was 4 hours 12 mins (from 23:50 h to 04:02 h local time). What does it mean to …

Desert beauty revealed from space

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Who knew so much geography could be crammed into such a beautiful image as this one. Taken by ESA’s ENVISAT satellite, this image shows the mountains of Tibesti on the borders of Chad and Libya. First of all, the dominant blue smudge are the mountains themselves – the highest range in the Saraha. Most have been created by now-dormant volcanoes, but some are still active in the region. Lava flows can just be seen on the western edge, flowing to the left. The highest peak – Emi Koussi can be seen as a darker circle in the lower right part of the dark area. Emi Koussi is a really interesting volcano, as scientists believe it is a good analogue Elysium Mons – one of the largest volcano on Mars. The white area at the top of the image is a depression in the landscape, caused by accumulating carbonate salts blown off the surrounding regions. When these carbonates dissolve in water …

Lightning is really really fast

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In case you didn’t already know it, lightning travels incredibly fast. Although this video is 33 seconds long, in reality, this event happened in only a little over 0.1seconds. What to us look like a simple flash of light, when slowed down 300x, is really an incredibly beautiful and complex phenomenon. There are a number of theories about how lightning originates, but all involve a build up of charge in the atmosphere. This, in itself, isn’t what causes lighning. What does is the difference in charge between the atmophere and the ground. To equilise this charge differential, electrons need to flow downhill. This is what we see in the first half of the video. Electrons always like to flow down the path of least resistance, and want to find the shortest distance to the ground. However, the electrons in the cloud don’t know where this is, so we see a random, branching pattern reaching out in all directions. This downstroke …

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